propidium

Propidium is a quaternary ammonium analog of ethidium and functions as an intercalating dye with specific affinity for certain forms of DNA. It is primarily used in research settings as a fluorescent stain to differentiate between viable and non-viable cells by binding to nucleic acids (DNA and RNA). Propidium itself is not membrane-permeant, making it useful for identifying dead or damaged cells with compromised membranes. When used as the diiodide salt (propidium iodide), it exhibits strong fluorescence upon binding to DNA, which allows its application in flow cytometry, microscopy, and cell viability assays. Additionally, propidium can form fluorescent complexes with cholinesterase enzymes and acts as an acetylcholinesterase inhibitor[2].

Other names

3,8-diamino-5-(3-(diethylmethylammonio)propyl)-6-phenylphenanthridinium, quaternary ammonium analog of ethidium